The History of the Church is a vital part of the Orthodox Christian faith. Orthodox Christians are defined significantly by their continuity with all those who have gone before, those who first received and preached the truth of Jesus Christ to the world, those who helped to formulate the expression and worship of our faith, and those who continue to move forward in the unchanging yet ever-dynamic Holy Tradition of the Orthodox Church.

663 Emperor Constans II is last Eastern emperor to set foot in Rome; Constans II declares the Pope of Rome to have no jurisdiction over the Archbishop of Ravenna, since that city was the seat of the exarch, his immediate representative.

664 Synod of Whitby held in northern England, adopting Roman calendar and tonsures in Northumbria; Ionian monk Wilfrid appointed as Archbishop of York; death of Cedd.

698 Muslim conquest of Carthage; at Synod of Aquileia, bishops of the diocese of Aquileia end the Schism of the Three Chapters and return to communion with Rome; persecution of Christians in China under Empress Wu's strong pro-Buddhist policies (China had declared Buddhism the state religion in 691).

732 Muslim invasion of Europe stopped by Franks at Battle of Tours, establishing a balance of power between Western Europe, Islam and the Byzantine Empire.

733 Byzantine Emperor Leo the Isaurian withdraws the Balkans, Sicily and Calabria from the jurisdiction of the Pope in response to Pope Gregory III of Rome's support of a revolt in Italy against iconoclasm.

734 Egbert becomes bishop of York, founding a library and making the city a renowned centre of learning.

747 The Witenagamot of England again forbids appeals to the Roman Patriarch ; Council of Clovesho I adopts Roman calendar, observance of the feasts of St. Gregory the Great and Augustine of Canterbury, and adopts the Rogation Days.

754 Iconoclastic Council held in Constantinople under the authority of Emperor Constantine V Copronymus, condemning icons and declaring itself to be the Seventh Ecumenical Council; Constantine begins dissolution of the monasteries.

787 Seventh Ecumenical Council held in Nicea, condemning iconoclasm and affirming veneration of icons; two councils held in England, one in the north at Pincanhale, and the other in the south at Chelsea, reaffirming the faith of the first Six Ecumenical Councils (the decrees of the Seventh having not yet been received), and establishing a third archbishopric at Lichfield.

800 Ambassadors of Caliph Harunu al-Rashid give keys to the Holy Sepulchre to Charlemagne, acknowledging some Frankish control over the interests of Christians in Jerusalem ; establishment of the Western Rite Monastery of Saint Mary in Jerusalem.

803 Council of Clovesho II abolishes archbishopric of Lichfield, restoring the pattern of the two metropolitan archbishoprics (Canterbury and York) which had prevailed before 787, and requires the use of the Western Rite amongst the English speaking peoples.

810 Pope Leo III refused permission for the Filioque to be inserted in the Creed.

ca. 839 First Rus'-Byzantine War, where the Rus attacked Propontis (probably aiming for Constantinople) before turning east and raiding Paphlagonia.

Notes

Some of these dates are necessarily a bit vague, as records for some periods are particularly difficult to piece together accurately.

The division of Church History into separate eras as done here will always be to some extent arbitrary, though it was attempted to group periods according to major watershed events.

This timeline is necessarily biased toward the history of the Orthodox Church, though a number of non-Orthodox or purely political events are mentioned for their importance in history related to Orthodoxy or for reference.